The subject matter herein relates generally to terminal crimping devices using ultrasonic transducers.
Terminals are typically crimped onto wires by means of a conventional crimping press having an anvil for supporting the electrical terminal and a ram that is movable toward and away from the anvil for crimping the terminal. In operation, a terminal is placed on the anvil, an end of a wire is inserted into the ferrule or barrel of the terminal, and the ram is caused to move toward the anvil to the limit of the stroke of the press, thereby crimping the terminal onto the wire. The ram is then retracted to its starting point.
New technologies in ultrasonic monitoring have been proposed for use in crimp quality monitoring. For example, U.S. Pat. No. 7,181,942 describes an ultrasonic device and method for measuring crimp connections by comparing signals with signals from a previous crimp that was determined to be desirable through destructive testing.
Such ultrasonic monitoring systems are not without disadvantages. For instance, the ultrasonic acoustic signals are passed through the ram and anvil and across the boundaries of such crimp tooling with the terminal. Due to the complex shape of the crimp tooling required to deform the electrical terminal during the crimping process, the ultrasonic acoustic signals are reflected and echo off of the surfaces in many directions causing noise in the received signal. The signal reflections decrease the signal-to-noise ratio of the received signal and reduce the effectiveness of the analysis methods to detect crimp anomalies. Reduction in signal quality reduces the ability to detect quality errors which the ultrasonic monitoring system is designed to detect.
A need remains for a crimp quality monitoring system having improved signal reception at the receiving transducer.